A family on their way back from a family gathering Monday night was gunned down in the Back of the Yards neighborhood, leaving a pregnant mother and grandmother dead and three others — including an 11-month-old boy — injured, police said.

The shooting spurred an emergency medical services response to the 5300 block of South Aberdeen Street after multiple people were reportedly shot at 7:15 p.m., said Chicago Fire Department Cmdr. Frank Velez.

Deputy Chief of Detectives Eugene Roy said that a group was returning from a family outing and getting out of their parked vehicle when another vehicle drove up and shots rang out from inside.

The boy’s mother, Patricia Chew, was shot in the right side, and the boy’s grandmother, Lolita Wells, was shot in the leg, according to relatives and police. Both were pronounced dead at Stroger Hospital. Relatives said Chew was 25 and Wells was 48. Police said the mother was 24 and the grandmother was 46.

“Coming home from a family outing, this family was attacked by unknown individuals,” Roy said. “In a second, two generations of that child’s family were wiped out.”

In addition to those victims, a 25-year-old man was shot in both legs and was taken to Mount Sinai Hospital and a 25-year-old man was taken to Mount Sinai Hospital with a gunshot wound to the abdomen. One of the men was in critical condition, while the other man had non-life-threatening injuries, Roy said.

No one was in custody, and it’s not immediately clear if family was being targeted.

A police officer took the 11-month-old boy, Princeton Chew, to Stroger Hospital with a gunshot wound to the side. The child’s condition had stabilized, police said. The baby underwent a CT scan and has non-life-threatening injuries.

Princeton was up and talking late Monday evening, said family members as they stood outside Stroger. The boy was going to stay at the hospital for observation overnight, they said. “The officer saw a seriously injured 11-month-old child and made a decision to transport that child immediately to a hospital. He made the right call, and he is somebody we are very proud of,” said Roy.

Earlier information incorrectly indicated that a second child had been injured in the shooting.

The EMS Plan 1 response called for at least six ambulances to the area, which was secured at 7:50 p.m., Velez said.

Red and yellow police tape blocked off both sides of South Aberdeen Street, stretching down the block toward West 54th Street.

Scene of a multi-victim shooting in 5300 block of South Aberdeen Street on Sept. 28, 2015. Five people were shot, including an 11-month-old, officials said.